20 CFR § 416.1600 - Introduction.
You are eligible for supplemental security income (SSI) benefits if you meet the requirements in subpart B. Among these are requirements that you must be a resident of the United States and either a citizen, a national, or an alien with a lawful right to reside permanently in the United States. In this subpart, we tell you what kinds of evidence show that you are a resident of the United States (see § 416.1603) and -
(a) A citizen or a national of the United States (see § 416.1610);
(b) An alien lawfully admitted for permanent residence in the United States (see § 416.1615); or
(c) An alien permanently residing in the United States under color of law (see § 416.1618).